Project WEAVING A TIMELINE FOR PERU

On the coast of Peru, some 100 miles north of Lima, archeologists are uncovering a major center of ancient civilization, dating as far back as 3000 B.C. It's the oldest known organized society in the entire Andean region. More than 20 large sites, featuring monumental architecture and large circular ceremonial structures, are clustered along four valleys. Lyra's parents, Jonathan Haas from Chicago's Field Museum and Winifred Creamer of Northern Illinois University, are leading the investigations of several sites.

"I've been working in the field with my parents practically since I was born," says Lyra. When she joined them at their Peru digs last summer, her father tossed her an important problem: how to date the inhabitation of different strata at the various sites. Elsewhere in Peru, the style of ceramic vessels is a common yardstick. But Norte Chico is pre-ceramic — all the sites had been abandoned before ceramics appeared. Textile remnants are fairly common finds, and snippets have been cut from some of them for radiocarbon dating. But Jonathan wanted to avoid that whenever possible.

By analyzing the fabric swatches that had been dated with radiocarbon techniques, Lyra came up with a classification method that enables researchers to date a fabric visually. Certain combinations of selected features — the type of yarn twining, the direction of yarn twist, and the direction of warp-yarn plying — are distinctive for different stages of the Norte Chico civilization, she found. Her checklist is now used by archeologists studying this important cradle of New World civilization.